I recently started having issues with the Apple TV app on my ONN Roku tv. It crashes immediately on startup. I have uplugged the device; I removed the app, rebooted the tv from settings, and reinstalled (in that order); I also cannot airplay to this device anymore. My Hisense and TCL branded tvs are not experiencing this issue. My guess is a firmware issue either on the Roku side or Apple side. Which i do not know. My guess is the Roku side but more specifically with ONN models 100044717 and related.
**FIXED**
I had to perform a hard reset using the tiny button on side of the tv by the USB port. to reset the tv and start fresh.